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Radiator Electric Fan Switch

lewis

lewis

Fight Till You Die
Location
Hairyman
What is available for fan switcheds out there? Trying to get some fans to turn on without a toggle. Had a fna switch with a thermocouple on there but it couldn't handle the amps to get the fan moving at high speeds. Tried doing some searching but haven't come up with anything.
 
mombobuggy

mombobuggy

Well-Known Member
Location
Highland
I am a little hesitant to answer this some R.M.E. members are electrical engineers and much more qualified than myself in this area . And I will be interested in there responses. I have seen some heavy duty switches that might be able to handle the load but it seems to me you are going to need a solenoid with the correct ampere rating. and some way to supply control power like an adjustable temp switch like the one summit sells for twenty dollars. Depending on memory to turn on the fans has been the cause of a lot of badly over heated motors.
 
I Lean

I Lean

Mbryson's hairdresser
Vendor
Location
Utah
I've used 85A continuous duty solenoids before with good luck. (after 40A relays wouldn't handle it)

If you want something cool, the DC Controls variable-speed setup looks pretty neat....varies the fan speed with motor temp, digitally.
 
lewis

lewis

Fight Till You Die
Location
Hairyman
I Lean said:
I've used 85A continuous duty solenoids before with good luck. (after 40A relays wouldn't handle it)

If you want something cool, the DC Controls variable-speed setup looks pretty neat....varies the fan speed with motor temp, digitally.
Click to expand...

Ya tried to order from DC controls, however their customer is not good and ended up having to get the money back from paypal since they never shipped the part, wouldn't respond to emails or phone calls. This isn't for me by the way its for my brother. He was the one that ordered from them. I will tell him about the solenoids though.
 
TurboMinivan

TurboMinivan

Still plays with cars
Location
Lehi, UT
jeep-N-montero said:
There are some great write-ups online where folks have had great luck with the dual speed relay setup from a late 90's Volvo
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THIS.

Were I to do another electric fan conversion--and someday I might, since I have T-bird 2spd fan sitting in the garage--I would use the Volvo setup to control it.
 
mbryson

mbryson

.......a few dollars more
Supporting Member
Location
Bountiful, land of rocks
Herzog said:
I use this 85A continuous solenoid with a lead right off the batt. Works very well and the fan spins right up with no noticeable drain/recovery. I do have it wired to always on when ignition on, but also have a kill switch wired in.
...I've never trusted a thermal switch for kicking on a fan, but I've also never used one.
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I have similar on my "Jeep" for the high speed side of the Taurus fan
 
Bobzilla

Bobzilla

Active Member
Location
Loma Colorado
I have am cooling a SB 305 chevy TBI engine, I used 2 relays 1 Taurus fan relay to power the electric fan which connects directly to the battery and one that is connected to the key switch to activate the Taurus high amp relay.

I installed a Index temperature control switch to activate the key switch relay it comes on at 195 degrees, the Index switch sends a ground to that relay, 195 degree switch is a normally open and can be used to send power or a ground to the relay, it is a 2-pole switch, (Index Temp Switch Part no. 8037026P 195 degree NO).

We used Index relays to power all electric fan relays on industrial applications on Cummins 8.9 litre & Cat C-9 diesel engines in Bombardier snowcats, the fan switch should activate after the engine thermostat is fully open, so the fan switch should activate 10-15 degrees above the thermostat on the engine to work best.

In addition I was informed by a local alternator rebuilder to use only a liquid filled battery in my application with the Taurus fan, they told me the Optima battery could not take the high amp charge from the alternator when the fan was activated, my fan as setup draws 60 amps on startup and 30 amp continuous while running. He said he would not warranty my new 100 amp alternator if used with an Optima style battery because is would overheat the alternator.
 
I Lean

I Lean

Mbryson's hairdresser
Vendor
Location
Utah
Bobzilla said:
I
In addition I was informed by a local alternator rebuilder to use only a liquid filled battery in my application with the Taurus fan, they told me the Optima battery could not take the high amp charge from the alternator when the fan was activated, my fan as setup draws 60 amps on startup and 30 amp continuous while running. He said he would not warranty my new 100 amp alternator if used with an Optima style battery because is would overheat the alternator.
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This doesn't make sense to me....why would the alternator care what kind of battery is in the loop? If it's providing the current to run a 30A draw, then it's providing 30A. That 30A is not charging any battery, it's running a fan. :confused:
 
Bobzilla

Bobzilla

Active Member
Location
Loma Colorado
I Lean said:
This doesn't make sense to me....why would the alternator care what kind of battery is in the loop? If it's providing the current to run a 30A draw, then it's providing 30A. That 30A is not charging any battery, it's running a fan. :confused:
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I am not an alternator rebuilder his professional opinion I will try and explain, he said that a an AGM battery such as the Optima brand is not capable of taking a high amp quick charges that happen with high amp demands, he said that the Optima battery can not absorb those kind of amps. He said that the Optima style of battery is better suited with low amp charging from the alternator and also when put on a battery charger.

He said what happens in my case with the 60 amp draw, the Optima battery cannot absorb or take the charge so the alternator has to absorb the heat created and begins to overheat and burn up, the more the fan cycles the higher the temps get in the alternator, I did do heat testing with the Optima battery and my wet Interstate battery and found what he was telling me was true. He said the old style batteries will absorb high amp quick charging and allow the alternator to operate cooler and prolong alternator life.

I hope that makes sense, it was news to me as I have been a mechanic for over 35 years, when I told him how I was setting up my rig, he told me he would warranty the 100 amp alternator for 3 years 100% parts & labor if I used a good quality acid filled battery, he told me if I used an Optima type battery that he would not warrant the alternator if it failed due to overheating caused by the AGM battery, like I said I am no alternator expert, he was just trying to help me and it has worked well for me.
 
mombobuggy

mombobuggy

Well-Known Member
Location
Highland
Great info. I have seen a lot of Electric fans that draw excessive amps due to there condition. High Miles.Or harsh treatment like mud. will make them not spin freely causing the fan to overheat its power source/wiring. relay. fusible link or fuse. Cant begin to imagine how many motors have been destroyed because of this problem. I don,t buy fans at the bone yard for this reason.
 
TurboMinivan

TurboMinivan

Still plays with cars
Location
Lehi, UT
Bobzilla said:
he said that a an AGM battery such as the Optima brand is not capable of taking a high amp quick charges that happen with high amp demands, he said that the Optima battery can not absorb those kind of amps. He said that the Optima style of battery is better suited with low amp charging from the alternator and also when put on a battery charger.
Click to expand...

This notion seems to fly directly in the face of conventional wisdom. So many four wheelers (including me) flock to AGM batteries after we install a winch. I admit I am no electrical engineer, but I would think a winch might be classified as a 'high amp demand' device. If it is--and if your overheating alternator theory is correct--then why don't AGM/winch users keep killing their alternators again and again and again? :confused:
 
Bobzilla

Bobzilla

Active Member
Location
Loma Colorado
TurboMinivan said:
This notion seems to fly directly in the face of conventional wisdom. So many four wheelers (including me) flock to AGM batteries after we install a winch. I admit I am no electrical engineer, but I would think a winch might be classified as a 'high amp demand' device. If it is--and if your overheating alternator theory is correct--then why don't AGM/winch users keep killing their alternators again and again and again? :confused:
Click to expand...

Great question, the rebuilder I spoke with said that is why many rigs are using dual Optima batteries with over 100 amp alternators, there are guys running over 200 amp alternators. That is why he made the point to me, I asked him if he had any 130 to 150 amp alternators, he asked exactly what I was doing and he told me I could pay a couple hundred bucks for a 130 to 150 amp alternator and he told me I would still burn up the alternator with the Optima battery.

He told me all I needed to run my lights, winch and Taurus fan was a 100 amp alternator with the standard single battery, he saved me some cash and it works well. We need someone to chime in who knows more and can explain this better than me.
 
thenag

thenag

Registered User
Location
Kearns
TurboMinivan said:
This notion seems to fly directly in the face of conventional wisdom. So many four wheelers (including me) flock to AGM batteries after we install a winch. I admit I am no electrical engineer, but I would think a winch might be classified as a 'high amp demand' device. If it is--and if your overheating alternator theory is correct--then why don't AGM/winch users keep killing their alternators again and again and again? :confused:
Click to expand...

I'll pile on with if AGM batteries would trash an alternator with an electric fan wouldn't all of the new vehicles that DO NOT have mechanical fans say something about voiding warranties if a AGM/Gel was used? I am pretty sure if AGM/Gel was bad for modern electric fan vehicles they wouldn't be on the market for long...

Do the new f150's have mechanical fans? If not I am sure someone on here can look through their owners manual for a disclaimer.

Nathan
 
flexyfool

flexyfool

GDW
Location
Boise, Idaho
Bobzilla said:
He said what happens in my case with the 60 amp draw, the Optima battery cannot absorb or take the charge so the alternator has to absorb the heat created and begins to overheat and burn up, the more the fan cycles the higher the temps get in the alternator, I did do heat testing with the Optima battery and my wet Interstate battery and found what he was telling me was true. He said the old style batteries will absorb high amp quick charging and allow the alternator to operate cooler and prolong alternator life.
Click to expand...

In other words, his "100 amp" alternator is really not a 100 amp alternator. It needs the battery to handle a 60 amp startup load. I would think any battery would be able to quickly provide 60 amps.
 
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